/* ========================================================================

 * Bootstrap: scrollspy.js v3.0.0

 * http://twbs.github.com/bootstrap/javascript.html#scrollspy

 * ========================================================================

 * Copyright 2012 Twitter, Inc.

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 * http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 * ======================================================================== */

+function ($) { "use strict";

  // SCROLLSPY CLASS DEFINITION

  // ==========================

  function ScrollSpy(element, options) {

    var href

    var process  = $.proxy(this.process, this)

    this.$element       = $(element).is('body') ? $(window) : $(element)

    this.$body          = $('body')

    this.$scrollElement = this.$element.on('scroll.bs.scroll-spy.data-api', process)

    this.options        = $.extend({}, ScrollSpy.DEFAULTS, options)

    this.selector       = (this.options.target

      || ((href = $(element).attr('href')) && href.replace(/.*(?=#[^\s]+$)/, '')) //strip for ie7

      || '') + ' .nav li > a'

    this.offsets        = $([])

    this.targets        = $([])

    this.activeTarget   = null

    this.refresh()

    this.process()

  }

  ScrollSpy.DEFAULTS = {

    offset: 10

  }

  ScrollSpy.prototype.refresh = function () {

    var offsetMethod = this.$element[0] == window ? 'offset' : 'position'

    this.offsets = $([])

    this.targets = $([])

    var self     = this

    var $targets = this.$body

      .find(this.selector)

      .map(function () {

        var $el   = $(this)

        var href  = $el.data('target') || $el.attr('href')

        var $href = /^#\w/.test(href) && $(href)

        return ($href

          && $href.length

          && [[ $href[offsetMethod]().top + (!$.isWindow(self.$scrollElement.get(0)) && self.$scrollElement.scrollTop()), href ]]) || null

      })

      .sort(function (a, b) { return a[0] - b[0] })

      .each(function () {

        self.offsets.push(this[0])

        self.targets.push(this[1])

      })

  }

  ScrollSpy.prototype.process = function () {

    var scrollTop    = this.$scrollElement.scrollTop() + this.options.offset

    var scrollHeight = this.$scrollElement[0].scrollHeight || this.$body[0].scrollHeight

    var maxScroll    = scrollHeight - this.$scrollElement.height()

    var offsets      = this.offsets

    var targets      = this.targets

    var activeTarget = this.activeTarget

    var i

    if (scrollTop >= maxScroll) {

      return activeTarget != (i = targets.last()[0]) && this.activate(i)

    }

    for (i = offsets.length; i--;) {

      activeTarget != targets[i]

        && scrollTop >= offsets[i]

        && (!offsets[i + 1] || scrollTop <= offsets[i + 1])

        && this.activate( targets[i] )

    }

  }

  ScrollSpy.prototype.activate = function (target) {

    this.activeTarget = target

    $(this.selector)

      .parents('.active')

      .removeClass('active')

    var selector = this.selector

      + '[data-target="' + target + '"],'

      + this.selector + '[href="' + target + '"]'

    var active = $(selector)

      .parents('li')

      .addClass('active')

    if (active.parent('.dropdown-menu').length)  {

      active = active

        .closest('li.dropdown')

        .addClass('active')

    }

    active.trigger('activate')

  }

  // SCROLLSPY PLUGIN DEFINITION

  // ===========================

  var old = $.fn.scrollspy

  $.fn.scrollspy = function (option) {

    return this.each(function () {

      var $this   = $(this)

      var data    = $this.data('bs.scrollspy')

      var options = typeof option == 'object' && option

      if (!data) $this.data('bs.scrollspy', (data = new ScrollSpy(this, options)))

      if (typeof option == 'string') data[option]()

    })

  }

  $.fn.scrollspy.Constructor = ScrollSpy

  // SCROLLSPY NO CONFLICT

  // =====================

  $.fn.scrollspy.noConflict = function () {

    $.fn.scrollspy = old

    return this

  }

  // SCROLLSPY DATA-API

  // ==================

  $(window).on('load', function () {

    $('[data-spy="scroll"]').each(function () {

      var $spy = $(this)

      $spy.scrollspy($spy.data())

    })

  })

}(window.jQuery);